Default on functionality
Default on functionality
(OP)
I am building a DSP driven motor controller and I am looking for a way to implement fail on functionality. Currently the DSP controls a triac that turns on and off when needed. Unfortunately, it is driven by the on board power supply and in the event of a controller or power supply failure I would like the unit to continue to provide power to the load. So far the only solution I can come up with still requires the on board power supply to drive the triac when it is supposed to be on. This works if the error is in the DSP chip, but on a power supply failure it still turns off the load. Any ideas would be greatly appreciated.





RE: Default on functionality
TTFN
RE: Default on functionality
If you must do this then why not add an external triggering circuit for the triac which is powered from the a.c. supply for the motor? (This would be normally gated off when the controller is functioning normally.)
RE: Default on functionality
Brian's comments are good--do you want the motor to run when there is a fault?
BigTom
RE: Default on functionality
RE: Default on functionality
TTFN
RE: Default on functionality